Comment 4 for bug 247088

The critical bit is gs-manager.c:1106 - it releases the pointer grab when the dialog comes up and re-grabs it again when the dialog goes down. Its not held while the dialog is up, otherwise the button in the unlock dialog become unclickable. The keyboard grab is still held and the key events are forwarded to the dialog via forward_key_events() in gs-window-x11.c:1151.